Sonic, Knuckles, and Tails reunite against a powerful new adversary, Shadow, a mysterious villain with powers unlike anything they have faced before. With their abilities outmatched, Team Sonic must seek out an unlikely alliance.

When the manic Dr Robotnik returns to Earth with a new ally, Knuckles the Echidna, Sonic and his new friend Tails is all that stands in their way.

After discovering a small, blue, fast hedgehog, a small-town police officer must help it defeat an evil genius who wants to do experiments on it.